Core coating



Patented Aug. 19, 1,924.

UN'ITD STATES PATENT OFFICE.

DANIEL H. MELOCHE, 015 DETROIT, MICHIGAN, ASSIGNOR TO EARL HOLLEY, OF

No Drawing.

To all whom it may concern:

DETROIT, MICHIGAN.

CORE COATING.

Application filed December 26, 1922. Serial No. 609,146.

Be it known that I, DANIEL H. MEIDOHE, ide-light.

a citizen of the United States, residing at 2241 Gladstone Ave, Detroit, in the county of Wayne and State of Michi an, have invented certain new and use ul Improve ments in Core Coatings, of which the followmg is a specification.

This invention relates to means for protecting the surface of dry sand cores from the erosive action of molten cast iron. This around the core.

invention is particularly adapted for use in heated molten iron.

conjunction with permanent iron molds in which grey iron castings are made. The coating consists of an inert insulating refractory, for example magnesium oxide, suspended in water to which a little glutrin is added. The exact proportions which I have found most satisfactory for small cores approximately 1" in diameter is" to mix four ounces of ma arch 31, 1922. What I claim is:

cores are then heated in a core oven so as to tity of glutrin.

thoroughly dry the coating. The ma nesium oxide, by reason of its excellent re actory and insulating qualities, forms a protective coatin core are not ii palpable powder known as magnesium 0x- The use of the 'lutrin renders the coating of magnesium oxide firmly adherent, hence the cores can be handled without the coating coming of. and an intact coating is presented to the molten iron when it is poured When a coating of silica is used in place of magnesium oxide the coating of silica fuses under the erosive action of highly If fire clay is used the coating is not sufiiciently porous and the coating of fire clay prevents the core acting as a vent. The peculia r advantages of magnesium oxide are that it is not only a refractory insuiator but it also provides a porous coating which will not in terfere with the core acting as a vent. v

I This application is based upon my cognesium oxide to a gallon of pfnding application, Serial No. 548,475, filed water containing 5% by volume of glutrin.

The dry sand cores are merel dipped into this mixture and on being withdrawn the 25 magnesium oxide, by reason of the presence of the glutrin, forms an adherent coating on the surface of the dry sand core. These 1. An insulating refractory Wash for coating dry sand cores consisting of a small quantity of light magnesium oxide powder suspended in water containing a small quan- 2. An insulating refractory wash for coat- 'ing dry sand cores consisting of an inert refractory powder suspended in water contain- Whereby particles of the sand ing a small percentage of glutrin to act as islodged and carried into the a binder. casting as is the case where less refractorv and less insulating coatings are provided. ture.

The magnesium oxide is obtained as an im- In testimony whereof I affix my signa- DANIEL H. MELOC-HE. 

